System and method for operating a steam turbine with a control system having a turbine simulator

ABSTRACT

A steam turbine is provided with an automatic digital computer control and a backup analog control which function in load and speed control loops during the positioning of the turbine inlet valves for speed and load control. An operator panel is provided with a test switch for transferring the turbine operation to backup control and for connecting the automatic control to a turbine simulator stored in the computer when it is desired to use the on-line computer for training, checkout or maintenance without disturbing the power generation process.

Uram

Oct. 7, 1975 SYSTEM AND METHOD FOR OPERATING A STEAM TURBINE WITH A CONTROL SYSTEM HAVING A TURBINE SIMULATOR OTHER PUBLICATIONS Application of the Prodac 50 System to Direct Digital 1 Inventors: RobertUram, East i b Pa. Control; .I. c. Belz, o. J. Kirk & P. s. Radcliffe, IEEE 1 Int]. Con Ree, Part 3, 1965, 102-122. [73] Assignee: Westinghouse Electric Corporation, pp

pimburgh Pa Momtormg and Automatic Control In Steam Power Stations by Process Computer, E. Doetsch & G. [22] Fil d p 1973 Hirschberg, Siemens Review XXXV (1968), No. 12, 1211 Appl. No.: 396,160 471-476 Primary ExaminerEugene G. Botz Related US Application Data Asszstant Exammer-Edward J. WIse A Attorney, Agent, or FIrmE. F. Possessky [63] ContInuatIon of Scr. No. 247,852, April 26, 1972,

abandoned.

[57] ABSTRACT [52] 290/40; 235/15121; 60/646; A steam turbine is provided with an automatic digital 444/1 computer control and a backup analog control which IIII. f i i d and speed control loops during the [58] held of Search 235/5121 15134 1513 positioning of the turbine inlet valves for speed and 235/15 1; 415/17; 60/64 66; 290/40 load control. An operator panel is provided with a test 40 F; 340/1725; 444/1 switch for transferring the turbine operation to backup I control and for connecting the automatic control to a [56] References C'ted turbine simulator stored in the computer when it is de- UNITED STATES PATENTS sired to use the on-line computer for training, check- 3,552,872 l/l971 Giras et al. 415/17 out or maintenance without disturbing the power gen- 3,555,251 [/1971 Shavit v. 235/151 eration process. 3,561,216 2/1971 Moore, Jr. 60/73 D 3,564,273 2 1971 Cockrcll 415/17 x 39 Clams, 35 Drawing Flgures o e POWER lMPULSE DETECTOR PRESSURE l9 DETECTOR STEAM LOAD GVI - 2 20 11+ Q 22 .4 l I I H.F. LP. L2 :3 lgfig flfi TURBINE TURBINE TURBINE GENERATOR 5151-5 SECTION SECTION SECTION eve l STEAM REHEATER sv lV CONDENSER l ass 1 L L29 J C55 ol ANALOG DIGITAL SPEED SPEED DETECTOR DETECTOR 52 HYDRgl/JLIC 58] 1.59 355% ACTUATOR POSITI N 12. CONTROLS 44 I HYDRAULIC HYDRAULIC GOVVERNOR ACTUIAYI'ORS 56 AcTuAT Rs 49 11/ 7 posmou HIGH PRESSURE CONTROLS HYDRAULIC FLUID SUPPLY Berry 415/17 X U. S. Pat ent Oct. 7,1975 Sheet2 of 28 3,911,286

U.S. Patent -0 ;t. 7,1975 Sheet-4 of 28 3,911,286

mm OE US. Patent Oct. 7,1975 Sheet 5 of 23 3,911,286

US. Patent Oct. 7,1975 Sheet 6 of 28 3,911,286

US. Patent Oct. 7,1975 Sheet 7 Of28 3,911,286

"26 PLANT gm 2 COMMANDER TASK L DATA TAS K LINK I852 INTERRUPT T T ERROR f SE%L\J/%NNCTES OF PANEL LAMPS INTERRUPT PROGRAM "58x VALVE L I852] INTERRUPT PLANT CCI 15 suBROuTINE REFERENCfl .854 III2 m0 H28 I r r sTATus xf af gu PANEL PANEL LOGIC LI mgs TASK TASKS I NTERRUPT CONTACTS I9IO OPERATOR S SPEED PANEL "56 SELECTION TURBINE BUTTONS PROGRAM 2022 TRIP "so DECODER INTERRUPT L|85O f Z5553 I??? #0 TASK I CHANNEL \-20I8 85%? ERROR INTERRUPT I LQCELLEE B2 l CONTROL VALVES 1 MONITOR AUXILIARY TASK sTOP SYNCHRONIZER L 1 INITIAL TASK 52 {I814 sPOLOOP TI PRE-sET r LOAD VALVE FLASH cONTROL POSITON ./|8l2 L TASK OLOsE Gv H36 Hi6 ANALOG SCAN BREAKER H41] TASK OPEN NTERRuPT ATS 34 I L vIsuAL BREAKER DISPLAY TASK II40- ATs PERIODCS CONTAiT1OLtJTPUTS TEST ATS H48 42/ ANALOG H TAS K CONVERSION ANALOG 1 ROUTINE DISPLAY DIGITAL 1/0 PR RAMM R MEssAGE F n44 WRITER CONSOLE TASK LOGGING TRENO TYPEWRITER RECORDER Sheet 11 of 28 3,911,286

U.S. Patent Oct. 7,1975

U.S. Pat ent 00. 7,1975 Sheet '17 of 22 3- 3,911,286

I24 /I I I0 SEQUENCE OF LOG: EVENTS TASK INTERRUPT PROGRAM CONTACT LOGIC mpuvs sures AUXILIARY 32 CONTROL MEL SYNCHRONIZER ANALOG OUTPUTS TASK EVERY TASK w,

sec Hi4 IOI2 ANALOG INPUTS ANALOG so: I

TASK Ans U.S. Pat ent 0m. 7,1975 Sheet 19 of 28 3,911,286

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1. A turbine for an electric power generating system comprising: a turbine for driving a plant generator, means for controlling the flow of an energizing fluid to said turbine, means for automatically controlling said flow controlling means to control the turbine speed during and after startup, means for automatically controlling said flow controlling means to control the turbine load after the turbine reaches synchronous speed, said automatic controlling means including means for generating electric signals for said flow controlling means as a function of reference and feedback signals, means for controlling the operation of said flow controlling means in response to the electric signals and in turn the operating state of said turbine, means for generating at least one simulated response to predetermined outputs generated by said automatic controlling means, means for connecting said automatic controlling and said generating means to operate in a simulation mode including means for applying the simulated response to said automatic controlling means, and means for operating said backup control means to control said turbine when said automatic controlling means is placed in the simulation mode.
 2. A turbine as set forth in claim 1 wherein the turbine is a steam turbine having inlet steam valves, said flow controlling means includes said valves, and said automatic controlling means provide position control over said valves.
 3. A turbine as set forth in claim 2 wherein said simulated response generating means is included as a part of said automatic controlling means.
 4. A turbine as set forth in claim 2 wherein said automatic controlling means includes a digital computer, said computer includes said simulated response generating means, and said backup control means is an analog control external to the computer.
 5. A control system as set forth in claim 4 wherein said automatic controlling means includes a digital computer, said computer includes said simulated response generating means, and said backup control means is an analog control external to the computer.
 6. A turbine as set forth in claim 2 wherein means are provided for generating a signal representing actual turbine speed, said automatic controlling means includes means for generating a speed demand as a function of a speed reference and the actual turbine speed, and said simulated response generating means includes meanS for generating a simulated turbine speed response as a function of the speed demand and for applying the simulated turbine speed response to speed demand generating means in place of the actual turbine speed when the simulation mode is selected.
 7. A turbine as set forth in claim 6 wherein said simulated turbine speed response generating means includes a first order lag function generator to which the speed demand is applied.
 8. A turbine as set forth in claim 6 wherein said automatic controlling means includes a digital computer, and computer includes said simulated response generating means, and said backup control means is an analog control external to the computer.
 9. A turbine as set forth in claim 2 wherein means are provided for generating a signal representing actual turbine load, said automatic controlling means includes means for generating a load demand as a function of a load reference and the actual turbine load, and said simulated response generating means includes means for generating a simulated turbine load response as a function of the load demand and for applying a simulated turbine load response to load demand generating means in place of the actual turbine load when the simulation mode is selected.
 10. A turbine as set forth in claim 9 wherein load demand is impulse pressure demand and the actual load is represented by impulse pressure.
 11. A turbine as set forth in claim 9 wherein the load demand is an electrical load demand and the actual load is represented by an electrical load signal.
 12. A turbine as set forth in claim 9 wherein said load demand generating means includes means for generating an electrical load demand as a function of an electrical load reference and actual electrical load and means for generating an impulse pressurue demand as a function of the electrical load demand and actual impulse pressure, said simulated response generating means includes an impulse pressure response generator and an electrical load response generator, and said electrical load and impulse pressure generators responding respectively to the electrcial load demand and the impulse pressure demand to generate respective simulated generator electrical load and turbine impulse pressure simulation responses for respective application to said electrical load and impulse pressure generators.
 13. A turbine as set forth in claim 12 wherein said automatic controlling means includes a digital computer, and said backup control means is an analog control external to the computer.
 14. A turbine as set forth in claim 9 wherein said simulated turbine speed response generating means includes a first order lag function generator to which the speed demand is applied.
 15. A turbine as set forth in claim 9 wherein means are provided for generating a signal representing actual turbine speed, said automatic controlling means includes means for generating a speed demand as a function of a speed reference and the actual turbine speed, and said simulated response generating means includes means for generating a simulated turbine speed response as a function of the speed demand and for applying the simulated turbine speed response to speed demand generating means in place of the actual turbine speed when the simulation mode is selected.
 16. A turbine as set forth in claim 15 wherein said automatic controlling means includes a digital computer, and said backup control means is an analog control external to the computer.
 17. A turbine as set forth in claim 9 wherein said automatic controling means includes a digital computer, and said backup control means is an analog control external to the computer.
 18. A turbine as set forth in claim 1 wherein an operator panel is provided with means for generating a simulation mode selection signal, means are provided for coupling said selection means to said automatic controlling means and said simulation response generating means.
 19. A turbine as set forth in claim 18 wherein the turbine is a steam Turbine having inlet steam valves, said flow controlling means includes said valves, and said automatic controlling means provide position control over said valves.
 20. A turbine as set forth in claim 18 wherein said automatic controlling means includes a digital computer, said computer includes said simulated response generating means, and said backup control means is an analog control external to the computer.
 21. A control system for a steam turbine having inlet steam valves, said control system comprising: means for controlling the flow of an energizing fluid to said turbine, means for automatically controlling said flow controlling means to control the turbine speed during and after startup, means for automatically controlling said flow controlling means to control the turbine load after the turbine reaches synchronous speed, said automatic controlling means including means for generating electric signals for said flow controlling means as a function of reference and feed back signals, means for controlling the operation of said flow controlling means in response to the electrical signals and in turn the operating state of said turbine, means for generating at least one simulated response to predetermined outputs generated by said automatic controlling means, means for connecting said automatic controlling and said generating means to operate in a simulation mode including means for appling the simulated response to said automatic means, and means for operating said backup control means to control said turbine when said automatic controlling means is placed in the simulation mode.
 22. A control system as set forth in claim 21 wherein the turbine is a steam turbine having inlet steam valves, said flow controlling means includes said valves, and said automatic controlling means provide position control over said valves.
 23. A control system as set forth in claim 22 wherein an operator panel is provided with means for generating a simulation mode selection signal, means are provided for coupling said selection means to said automatic controlling means and said simulation response generating means.
 24. A turbine as set forth in claim 21 wherein means are provided for generating a signal representing actual turbine speed, said automatic controlling means includes means for generating a speed demand as a function of a speed reference and the actual turbine speed, and said simulated response generating means includes means for generating a simulated turbine speed response as a function of the speed demand and for applying the simulated turbine speed response to speed demand generating means in place of the actual turbine speed when the simulation mode is selected.
 25. A control system as set forth in claim 24 wherein said simulated turbine speed response generating means includes a first order lag function generator to which the speed demand is applied.
 26. A control system as set forth in claim 24 wherein said automatic controlling means includes a digital computer, said computer includes said simulated response generating means, and said backup control means is an analog control external to the computer.
 27. A control system as set forth in claim 24 wherein said automatic controlling means includes a digital computer, said computer includes said simulated response generating means, and said backup control means is an analog control external to the computer.
 28. A control system as set forth in claim 24 wherein an operator panel is provided with means for generating a simulation mode selection signal, means are provided for coupling said selection means to said automatic controlling means and said simulation response generating means, and said operator panel includes means for generating a speed reference signal and means for coupling the speed reference signal to said automatic controlling means during turbine startup.
 29. A control system as set forth in claim 28 wherein means are provided for Automatically generating a speed reference during turbine startup, and said operator panel includes means for generating an automatic startup select signal which is applied to said automatic controlling means.
 30. A control system as set forth in claim 28 wherein said operator panel includes means for generating a load reference signal and means for coupling the load reference signal to said automatic controlling means during the turbine load mode.
 31. A control system as set forth in claim 21 wherein means are provided for generating a signal representing actual turbine load, said automatic controlling means includes means for generating a load demand as a function of a load reference and the actual turbine load, and said simulated response generating means includes means for generating a simulated turbine load response as a function of the load demand and for applying the simulated turbine load response to load demand generating means in place of the actual turbine load when the simulation mode is selected.
 32. A control system as set forth in claim 31 wherein load demand is impulse pressure demand and the actual load is represented by impulse pressure.
 33. A control system as set forth in claim 31 wherein the load demand is an electrical load demand and the actual load is represented by an electrical load signal.
 34. A control system as set forth in claim 31 wherein said load demand generating means includes means for generating an electrical load demand as a function of an electrical load reference and actual electrical load and means for generating an impulse pressure demand as a function of the electrical load demand and actual impulse pressure, said simulated response generating means includes an impulse pressure response generator and an electrical load response generator, and said electrical load and impulse pressure generators responding respectively to the electrical load demand and the impulse pressure demand to generate respective simulated generator electrical load and turbine impulse pressure simulation responses for respective application to said electrical load and impulse pressure generators.
 35. A control system as set forth in claim 34 wherein said automatic controlling means includes a digital computer, said computer incudes said simulated response generating means, and said backup control means is an analog control external to the computer.
 36. A control system as set forth in claim 31 wherein said simulated turbine speed response generating means includes a first order lag function generator to which the speed demand is applied.
 37. A control system as set forth in claim 31 wherein means are provided for generating a signal representing actual turbine speed, said automatic controlling means includes means for generating a speed demand as a function of a speed reference and the actual turbine speed, and said simulated response generating means includes means for generating a simulated turbine speed response as a function of the speed demand and for applying the simulated turbine speed response to speed demand generating means in place of the actual turbine speed when the simulation mode is selected.
 38. A control system as set forth in claim 31 wherein said automatic controlling means includes a digital computer, said computer includes said simulated response generating means, and said backup control means is an analog control external to the computer.
 39. A control system as set forth in claim 31 wherein an operator panel is provided with means for generating a simulation mode selection signal, means are provided for coupling said selection means to said automatic controlling means and said simulation response generating means, and said operator panel includes means for generating a load reference signal and means for coupling the load reference signal to said automatic controlling means during the turbine load mode. 